1. Field
Various exemplary embodiments of the present disclosure relate to a transistor, and more particularly, to a dual work function buried gate type transistor and a method for fabricating the same.
2. Description of the Related Art
A metal gate electrode may be applied as the gate electrode of a transistor. Since a metal gate electrode has low resistance, gate resistance may be decreased. Additionally, since a metal gate electrode may have a high work function, the channel dose may be decreased. Thus, leakage current may be reduced, and the performance of the transistor may be improved.
However, there may be issues caused by the high work function, since gate-induced drain leakage (GIDL) increases where the metal gate electrode and source/drain regions overlap. Particularly, in a buried gate type transistor, since the overlap area between the buried metal gate electrode and source/drain regions is large, gate-induced drain leakage (GIDL) may be an issue.
To reduce gate-induced drain leakage (GIDL), the height of the buried metal gate electrode may be lowered. Accordingly, the overlap area between the buried metal gate electrode and the source/drain regions may be reduced.
However, if the height of the buried metal gate electrode is lowered, there may be a concern that the gate resistance increases and the current drivability of the transistor is degraded.
Hence, an improved trade-off between gate-induced drain leakage (GIDL) and current drivability is in demand.